The Biostatistics Support Core, previously called the Biometric Support Unit, has maintained the Bone Marrow Transplant Research Database since the beginning of the program project. The database contains information from all patients who have received marrow transplants at University of Minnesota Hospital, information gathered with careful quality control procedures. An experienced staff of data technicians gather relevant information from clinical and laboratory records and from attending physicians. The Biostatistics Support Core also provides statistical support for the project, assisting in the design of clinical trials and in the statistical analysis of clinical or retrospective studies, and performing additional statistical analyses requested by the investigators in the program project.